This invention is directed to an inspection circuit for use in an electronic timepiece and, in particular, to an inspection circuit that permits each of the timekeeping counters in an electronic timepiece to be simultaneously inspected, and thereby shortens the time required to perform such inspection.
To the manufacturer of electronic timepieces, such as miniaturized electronic wristwatches and the like, quality control is deemed to be one of the most significant yet inefficient manufacturing operations. Heretofore, one typical method of performing quality control in an electronic wristwatch was to change over the electronic wristwatch from a normal display mode into a correction mode in order to inspect the operation of the timekeeping counters and the digital display digits. Specifically, in order to inspect the minutes display, the minutes display would be selected in a correction mode, and thereafter, sixty correction pulses would be applied thereto in order to index the minutes counter sixty times. Thereafter, the same operation would be repeated for the hours counters, date counter and month counter. By indexing each of the timekeeping counters when same are disposed in a correction mode, proper operation of the timekeeping counters and the digital display digits can easily be monitored.
It is noted, however, that this operation is highly inefficient. As the number of types of information displayed by electronic wristwatches has increased, the amount of time required to inspect an electronic wristwatch, in the manner detailed above, has likewise increased.
The inspection method detailed above is speeded up when the electronic wristwatch includes a rapid advance correction mechanism instead of the more widely utilized indexing type correction mechanisms. Specifically, in rapid advance correction mechanisms, an intermediate frequency signal higher than the usual one second low frequency timing signal applied to the seconds counter is applied to the specific timekeeping counter selected for correction and, hence, rapidly advances the count thereof. Although this type of rapid advance correction does increase the time of inspection it is still necessary to sequentially select each of the counters for correction and, furthermore, manufacturers often prefer to utilize the indexing type correction which is often favored by consumers. Accordingly, an inspection circuit for use in electronic timepieces that significantly decreases the time required to inspect the timekeeping counters and digital display elements during a quality control operation is desired.